Some great advice here, I as another novice even enjoyed reading all the helpful tips.

Regarding aperture, some lenses seem sharper around certain apertures, is this true? I don't have any very good quality lenses yet, still saving up for the next one, but it does seem to be the case with my kit lens.

you're right peteaarhus.. once you find the Aperature sweet spot of the lens adjust your ISO to reach the desired shutter speed and you really cant go wrong for wildlife photography. Once you got that down you can play more to vary the results/effects if you want to.

I haven't had much practice in the rule of thirds but i do get the concept just haven't obviously put it into practice, as for focus point I was using single point focus and aiming for the eyes of the animals I was shooting.

For my first time out I guess I am not too sad, hopefully as I return I can see the progress from my folders of pics each time till i get a few I am happy with.

Im not a DSLR user myself, but i think maybe you should go somewhere near you (to a park) on a sunny day and mess around with differant settings and see how they affect the picture, and then try to fix any mistakes.
Better yet, write all the advice you got here and mess around. Then when you feel cofidant that you know how to make a good picture, go to somewhere interesting and take pictures.
Then review them, put your results to practice again and slowly but surely reach perfection.